Despite advances in chemoradiation therapy, the five-year survival rate for esophageal squamous cell neoplasia (ESCN) remains a dismal 15% due to diagnosis at a late, incurable stage. Endoscopic screening is typically performed in high-risk populations with Lugol's iodine staining of the mucosa and targeted biopsy of abnormal (unstained) areas. While Lugol's significantly increases the sensitivity of white light endoscopy (>95%), specificity remains poor (<65%) as inflammation and other benign mucosal changes mimic neoplasia. While confocal microendoscopy has been shown to dramatically enhance the diagnostic accuracy and yield of Lugol's chromoendoscopy, existing platforms are costly (>$150,000) and only available in a handful of tertiary centers worldwide. Our group has developed a portable, battery-operated, high-resolution microendoscope (mHRME) that provides subcellular images of the esophageal epithelium, delineating the cellular and morphologic changes associated with neoplasia. In a recent, single-arm pilot trial (R21), the HRME significantly increased the sensitivity and specificity of Lugol's screening to 100% and 89%. Based on our extensive preliminary data, we now propose to optimize and validate a lower-cost (<$1600), tablet-based system with a software interface that provides real- time image interpretation assistance, thus facilitating usage by less-experienced clinicians in low-resource settings. Our central hypothesis is that this 'optical' approach will increase the efficiency, clinical impact, and cost-effectiveness of the current standard of endoscopic screening and surveillance. To validate this, we will conduct a randomized, multicenter trial of our 'optical biopsy' approach comparing it to the current standard of endoscopic screening/surveillance in the U.S. and China. In addition, we will construct, refine and analyze a disease model of ESCN to determine the effectiveness and cost-effectiveness of incorporating HRME into endoscopic screening and surveillance in both countries. Successful results can easily be translated to global cancer screening in other organs (cervix, colon, etc.).